Hyūga Sen lay on the operating table, turning his head to ask,"You're not using anesthesia? Will it hurt a lot?"Then he added, "I heard anesthesia can damage your intelligence."
Uchiha Kin replied calmly, "Yes, anesthesia does cause some degree of brain damage... I could sever your pain receptors, but I doubt you'd agree to that."
Kin reached into the wardrobe beside him and retrieved the surgical gown, gloves, and mask Hyūga Sen had prepared in advance. After putting them on, he secured his protective goggles.
"Wait..." Sen took a deep breath. "Let me take one last look at this world."
He stared up at the tent's ceiling for a moment, then gripped the side handles of the surgical table tightly with both hands.
"It's going to hurt—a lot," Kin reminded him. "You must endure it. Do not move. Not even a muscle twitch.You need to understand, even the slightest tremor could cause a misalignment during the nerve reattachment. One mistake, and everything we've done will be wasted."
Sen said firmly, "Don't underestimate a shinobi's endurance—忍 (nin) means to endure what others cannot. Watch closely: if I move even a hair, call me your grandson!"
Kin smirked. "If you don't move, you're a turtle."
That little joke eased the tension just a bit.
A clamp in the shape of the kanji for "return" forced Sen's eyelids open to their limit. A tearing pain shot from the nerves in his eyelids deep into his skull, his entire head throbbing in response.
Pale yellow threads of nerve tissue extended from Kin's palm and latched onto Sen's eyeball.
Like swift-moving worms, they crawled behind the eye, tunneling into the cranial cavity and forming a temporary bridge that bypassed not only the neural extensions created by the Caged Bird Seal—but also several other nerves.
Kin didn't bother trying to differentiate which nerve strands belonged to the Caged Bird Seal. He simply bypassed everything related.
Reroute.
Then, with a gentle stroke of the scalpel, he severed the connective tendons, and the entire eyeball—with its tangle of nerve tendrils—was pulled free.
Kin examined the eye in his hand briefly before turning away and placing it into a glass jar. He then retrieved a replacement eye and began the installation.
This time, the process was excruciatingly slow.
The human optic nerve is one of the most complex structures in the body. Carefully, strand by strand, Kin began connecting each nerve filament.
He was intimately familiar with the human nervous system. After all, his secret jutsu—Neural Manipulation Technique—was something he'd developed through years of painstaking research.
So how could he not understand nerves?
With meticulous sorting, Kin identified the unnatural nerves created by the Caged Bird Seal as extraneous.
He memorized their connection points one by one, and then began grafting Sen's new optic nerves alongside those of the seal.
Fine nerve roots—like delicate spider silk—spread outward. Sen, consumed by pain, didn't notice a thing.
"How fascinating," Kin muttered. "It's like a shackle, embedded deep into the brain. Countless tendrils... If the seal activates, the pain would be unbearable.And the energy source for this seal—it's the eyes.
"A specific nerve behind the Byakugan doesn't connect to the visual processing center. Instead, it routes to the forehead.These two eyes provide a constant stream of energy to the seal."
That same connection—the one feeding the Caged Bird Seal—was also the missing piece in the Branch Family's Byakugan. It was the reason their field of vision was incomplete—and the reason their ocular potential was stunted.
Kin redirected that energy source from the eyes to the heart.
Then, channeling Medical Sage Jutsu, he grafted the tendons and new eye together.
The pain faded.
However, the skin around the eye remained blood-red, and the spot where the tendons fused with the sclera was veined with blood, giving the eye a grotesque appearance.
"How does it feel?" Kin asked.
Sen blinked a few times with his new eye, then opened it wide. The world was now black and white—but the blind spots were gone.
What's more, the sensation was different than before. Now, when activating the Byakugan, he didn't feel any loss of chakra.It felt... full. Complete. No longer like a water pouch with a slow leak.
He couldn't help but smile in surprise. Comparing the new eye with his old one made the contrast even more startling.
A perfect field of view. A rejuvenated, vibrant eye. Though colorless, the world felt alive.
"This feeling is incredible! Quick, let's do the other eye—I can't wait any longer!"
Kin chuckled. "Very well."And once again, he performed the same procedure to transplant the other eye.
"Hahaha! The Byakugan... That damned Caged Bird Seal... it's finally gone. Kin, thank you—truly. My dearest friend!"
Sen beamed with unrestrained joy. He had schemed for this day for so long. He'd pushed Kin to learn medical ninjutsu, painstakingly gathered every scrap of data with his Byakugan.
He had poured countless resources into Kin. Invested everything for this very moment.
He was still smiling when a flash of cold steel swept by—and Uchiha Kin's throat was slit wide open.
"Such a pity. But my secret cannot be known to anyone. You'll have to join Nara Gyoku in the Pure Land."
He spoke softly.
"In a way, this is a blessing for you. The Uchiha are destined for extermination. No matter how hard you try, you'll never stop that lunatic.Better to die now than to live and witness the massacre of your clan.
"I know that helpless feeling all too well."
Kin's body collapsed, the strength draining from his limbs. He tried to support himself against the table and ended up slumped against it, barely sitting upright.
His lips moved—he wanted to say something...
Sen seemed to know what it was.He said quietly, "I prepared for this moment for a long time. That includes investing in you.I suppose... I should feel a little sad right now.
"But my dear friend, I can't afford to let someone who knows I've broken the Caged Bird Seal stay alive.
"I know you liked Kobayashi, Ozawa, Asami Yuma, and... well, don't worry. I'll send them down to keep you company.Enjoy yourself in the Pure Land."
He crouched down.The new Byakugan in his sockets no longer held that lifeless, hazy sheen. Now they shimmered with vitality.
"Kin, I know you never fully trusted me. We were always using and guarding against each other. I'm sure you had a backup plan just now too, right? But too bad… you lost.
"These eyes," he pointed at them proudly, "can see through everything. Under their gaze, no scheme or trick means anything."